High-sensitivity detection of tetracycline using phosphorus-doped carbon quantum dots prepared by pyrolysis method as fluorescent probes

Abstract The selective and highly sensitive detection of trace tetracycline antibiotic residues is crucial for ensuring food safety and maintaining organismal health. In the present study, we describe a novel method for tetracycline detection utilizing phosphorus-doped carbon quantum dots (P-CQDs) synthesized via solid-phase pyrolysis as fluorescent probes. Phosphorus doping significantly amplifies the fluorescence intensity by a factor of 8.1, and the resulting P-CQDs exhibit superior optical stability. The excitation and emission maxima of the P-CQDs are located at 340 nm and 440 nm, respectively. The fluorescent probe detects tetracycline based on the inner filter effect, demonstrating high selectivity and strong interference resistance. It has a wide detection range of 0–80 μM and a low detection limit of 0.120 μM. This method has been effectively applied to the analysis of real samples, yielding satisfactory results.